Concave pi-prismand hydrocarbon [2.2.2]cyclophanes and their crystalline Ag-triflate complexes

New small concave hydrocarbon cyclophanes were prepared via the well-known HD-2SO(2)-method(2)). The cyclophanes obtained are isomers of the very well -known [2.2.2]p,p,p-cyclophane, C24H24, a pi-prismand efficiently complexin g Ag+-ion. X-ray crystal structure determinations showed the his-sulfide 7 (1,10-dithia[3.3.2]m,p,p-cyclophane) to be helically chiral and that the co nformation of the parent hydrocarbon cyclophane 13 ([2.2.2]m,p,p-cyclophane ) does not change dramatically upon complexation with the AE(+)-ion, The 16 - and- 17-membered [2.2.2]m,m,p- and [2.2.2] m,p,p-cyclophane (15 and 16) a lso act as pi-prismands and form surprisingly similar crystalline 1:1 Ag-tr iflate complexes (pi-prismates) as the well-known 18-membered p,p,p-isomer proved by the X-ray structure analysis.